1 /*
2  * dwmac-stm32.c - DWMAC Specific Glue layer for STM32 MCU
3  *
4  * Copyright (C) Alexandre Torgue 2015
5  * Author:  Alexandre Torgue <alexandre.torgue@gmail.com>
6  * License terms:  GNU General Public License (GPL), version 2
7  *
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/kernel.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_device.h>
16 #include <linux/of_net.h>
17 #include <linux/phy.h>
18 #include <linux/platform_device.h>
19 #include <linux/regmap.h>
20 #include <linux/slab.h>
21 #include <linux/stmmac.h>
22 
23 #include "stmmac_platform.h"
24 
25 #define MII_PHY_SEL_MASK	BIT(23)
26 
27 struct stm32_dwmac {
28 	struct clk *clk_tx;
29 	struct clk *clk_rx;
30 	u32 mode_reg;		/* MAC glue-logic mode register */
31 	struct regmap *regmap;
32 	u32 speed;
33 };
34 
35 static int stm32_dwmac_init(struct plat_stmmacenet_data *plat_dat)
36 {
37 	struct stm32_dwmac *dwmac = plat_dat->bsp_priv;
38 	u32 reg = dwmac->mode_reg;
39 	u32 val;
40 	int ret;
41 
42 	val = (plat_dat->interface == PHY_INTERFACE_MODE_MII) ? 0 : 1;
43 	ret = regmap_update_bits(dwmac->regmap, reg, MII_PHY_SEL_MASK, val);
44 	if (ret)
45 		return ret;
46 
47 	ret = clk_prepare_enable(dwmac->clk_tx);
48 	if (ret)
49 		return ret;
50 
51 	ret = clk_prepare_enable(dwmac->clk_rx);
52 	if (ret)
53 		clk_disable_unprepare(dwmac->clk_tx);
54 
55 	return ret;
56 }
57 
58 static void stm32_dwmac_clk_disable(struct stm32_dwmac *dwmac)
59 {
60 	clk_disable_unprepare(dwmac->clk_tx);
61 	clk_disable_unprepare(dwmac->clk_rx);
62 }
63 
64 static int stm32_dwmac_parse_data(struct stm32_dwmac *dwmac,
65 				  struct device *dev)
66 {
67 	struct device_node *np = dev->of_node;
68 	int err;
69 
70 	/*  Get TX/RX clocks */
71 	dwmac->clk_tx = devm_clk_get(dev, "mac-clk-tx");
72 	if (IS_ERR(dwmac->clk_tx)) {
73 		dev_err(dev, "No tx clock provided...\n");
74 		return PTR_ERR(dwmac->clk_tx);
75 	}
76 	dwmac->clk_rx = devm_clk_get(dev, "mac-clk-rx");
77 	if (IS_ERR(dwmac->clk_rx)) {
78 		dev_err(dev, "No rx clock provided...\n");
79 		return PTR_ERR(dwmac->clk_rx);
80 	}
81 
82 	/* Get mode register */
83 	dwmac->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscon");
84 	if (IS_ERR(dwmac->regmap))
85 		return PTR_ERR(dwmac->regmap);
86 
87 	err = of_property_read_u32_index(np, "st,syscon", 1, &dwmac->mode_reg);
88 	if (err)
89 		dev_err(dev, "Can't get sysconfig mode offset (%d)\n", err);
90 
91 	return err;
92 }
93 
94 static int stm32_dwmac_probe(struct platform_device *pdev)
95 {
96 	struct plat_stmmacenet_data *plat_dat;
97 	struct stmmac_resources stmmac_res;
98 	struct stm32_dwmac *dwmac;
99 	int ret;
100 
101 	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
102 	if (ret)
103 		return ret;
104 
105 	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
106 	if (IS_ERR(plat_dat))
107 		return PTR_ERR(plat_dat);
108 
109 	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
110 	if (!dwmac)
111 		return -ENOMEM;
112 
113 	ret = stm32_dwmac_parse_data(dwmac, &pdev->dev);
114 	if (ret) {
115 		dev_err(&pdev->dev, "Unable to parse OF data\n");
116 		return ret;
117 	}
118 
119 	plat_dat->bsp_priv = dwmac;
120 
121 	ret = stm32_dwmac_init(plat_dat);
122 	if (ret)
123 		return ret;
124 
125 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
126 	if (ret)
127 		stm32_dwmac_clk_disable(dwmac);
128 
129 	return ret;
130 }
131 
132 static int stm32_dwmac_remove(struct platform_device *pdev)
133 {
134 	struct net_device *ndev = platform_get_drvdata(pdev);
135 	struct stmmac_priv *priv = netdev_priv(ndev);
136 	int ret = stmmac_dvr_remove(&pdev->dev);
137 
138 	stm32_dwmac_clk_disable(priv->plat->bsp_priv);
139 
140 	return ret;
141 }
142 
143 #ifdef CONFIG_PM_SLEEP
144 static int stm32_dwmac_suspend(struct device *dev)
145 {
146 	struct net_device *ndev = dev_get_drvdata(dev);
147 	struct stmmac_priv *priv = netdev_priv(ndev);
148 	int ret;
149 
150 	ret = stmmac_suspend(dev);
151 	stm32_dwmac_clk_disable(priv->plat->bsp_priv);
152 
153 	return ret;
154 }
155 
156 static int stm32_dwmac_resume(struct device *dev)
157 {
158 	struct net_device *ndev = dev_get_drvdata(dev);
159 	struct stmmac_priv *priv = netdev_priv(ndev);
160 	int ret;
161 
162 	ret = stm32_dwmac_init(priv->plat);
163 	if (ret)
164 		return ret;
165 
166 	ret = stmmac_resume(dev);
167 
168 	return ret;
169 }
170 #endif /* CONFIG_PM_SLEEP */
171 
172 static SIMPLE_DEV_PM_OPS(stm32_dwmac_pm_ops,
173 	stm32_dwmac_suspend, stm32_dwmac_resume);
174 
175 static const struct of_device_id stm32_dwmac_match[] = {
176 	{ .compatible = "st,stm32-dwmac"},
177 	{ }
178 };
179 MODULE_DEVICE_TABLE(of, stm32_dwmac_match);
180 
181 static struct platform_driver stm32_dwmac_driver = {
182 	.probe  = stm32_dwmac_probe,
183 	.remove = stm32_dwmac_remove,
184 	.driver = {
185 		.name           = "stm32-dwmac",
186 		.pm		= &stm32_dwmac_pm_ops,
187 		.of_match_table = stm32_dwmac_match,
188 	},
189 };
190 module_platform_driver(stm32_dwmac_driver);
191 
192 MODULE_AUTHOR("Alexandre Torgue <alexandre.torgue@gmail.com>");
193 MODULE_DESCRIPTION("STMicroelectronics MCU DWMAC Specific Glue layer");
194 MODULE_LICENSE("GPL v2");
195